


Decent Black

by Lycoria



Series: Moondust [1]
Category: Voltron: Legendary Defender
Genre: Anal Fingering, Anal Sex, Angst, Dark! Shiro, Dirty Talk, Dom/sub Undertones, Evil! Shiro, Foreplay, M/M, Masturbation, Multiple Sex Positions, Mutual Masturbation, PWP, Plot What Plot/Porn Without Plot, Rough Sex, Strip Tease, kuro - Freeform
Language: English
Status: Completed
Published: 2016-09-06
Updated: 2016-09-06
Packaged: 2018-08-13 08:40:05
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,656
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7969906
Author URL: https://archiveofourown.org/users/Lycoria/pseuds/Lycoria
Summary: <blockquote class="userstuff">
              <p>Being with Shiro was like being immortal, infallible. It felt right. </p><p>But sometimes, Keith couldn’t help but feel the need to fall.</p><p>(Dark! Shiro / Keith smut)</p>
            </blockquote>





	Decent Black

To Keith, being with Shiro was like being home while in entirely new galaxies, a universe far-reaching.

Shiro was like sitting near window in the winter, sipping on a hot drink and covered in a blanket, watching the grey dawn unfold on a new day.

Kisses Shiro gave him were made of starlight and smelled like freshly cut grass, something Keith never enjoyed back on Earth, but now yearned for in a way he didn’t realize he could.

Whispers in the dark, tangled hands and curled fingers when no one else was watching, made Keith feel like he was invincible, like their cosmic destinies had aligned in way that they would never part.

All of these things were things that Keith would never admit to anyone, much less himself.

It was only natural that Shiro and Keith gravitated towards each other. To the both of them, they were each other’s remaining slice of Earth. Sure, the paladins were each other’s support, but not like they were. Before Shiro had been abducted, before Keith had been expelled from the school, before the fight for the universe, Keith and Shiro had just been Keith and Shiro.

Shiro was the only one ever patient enough to understand Keith’s convoluted thoughts, and he was the only one that Keith let in. 

Being with Shiro was like being immortal, infallible. It felt _right_. 

But sometimes, Keith couldn’t help but feel the need to fall.

 

* * *

 

It was imperceptible at first, a hint of aggression here and there, nothing that seemed ordinary in the Paladin’s strained daily lives. Everyone had their off days, Lance and Keith’s in particular manifesting as shouting matches that threatened to shake the entire castleship apart. Hunk would mask his anxiety in long heated discussions with Coran about Altean History to cuisine and anything in between. Allura would nitpick at the paladins like a hovering, well-meaning mother, and Pidge would often nest herself amongst gadgets and technologies with her door securely shut. 

Everyone had their off days.

But not Shiro.

With strong arms he would pull Lance and Keith away from each other, reason silencing the dispute. On days when Hunk felt his own nerves unbearable, Shiro would come along and join Hunk and Coran, cajoling them into a friendly game of cards to keep their fears at bay. He would smile good-naturedly at Allura, reminding her that they were a group of rowdy teenagers, there was no sense in worrying over their every move. For Pidge, he’d leave her meals at the front of her door, and the plate would always be cleaned when he came back to check later.

To the others, Shiro’s patience and leadership seemed like an endless fount, wisdom from what he had seen graced him with a stoicism that the other paladin’s couldn’t help but admire. 

So of course it was Keith that noticed the changes, so slight, like scratches on a well worn mirror, or the shifting of tectonic plates on Earth. His friends, just like most earthly citizens, were mostly unaware of the tremors, leaving Keith to doubt by himself.

It was an over the shoulder throw that slammed Hunk harder into the training mat than the rest of the paladins anticipated, knocking the wind out the large young man. Everyone rushed to see if he was okay, including Shiro, the opponent that had thrown him in the first place. Hunk managed to give them all a thumbs up despite his wheezing, and Shiro had put out a hand to lift him up, apology clear in his eyes.

They blamed it on fatigue, which lead to the carelessness that characterized the strange amount of force he had applied to Hunk. Shiro’s teammates gave him hard slaps on the back, telling him that he needed to take a break himself.

Then there were times when, in the heat of a fight, Shiro barked commands rather than ordered them. The coldness of his voice always shocked Keith, but once again remained unnoticed to the rest, concentrated on the fight before them.

Maybe it was because Shiro was like the sun to Keith, and the harshness of these momentary slipups were as merciless as the unwavering moon.

 

* * *

 

Keith rolled over in his bed, sitting up to see space and stars in the open window across his room. Often times he would greet sleepless nights like this, staring at his personal portal into the void.

It was strange to think that at one point, all of them had been at the Galaxy Garrison, hoping and dreaming of the day when they too, like Shiro and the rest of the graduates, would go on their first mission into space. Now they were here, doing something more impossibly important than they could have ever imagined.

Keith only felt suffocated.

Some nights, Keith would find Shiro knocking at his door, a sheepish grin stretched on his features. They would talk awhile, Shiro’s head in his lap as he they clasped hands, watching the universe go by. Sometimes they would bring their heads together, sealing their lips with a kiss that lead to maybe more, maybe not.

On rarer nights, Keith would find him at his door too, but those times wearing an impenetrable, unreadable gaze.

A sharp rap sounded on his door, and Keith’s heart raced at the noise. There was no one else that would be looking for him this late at the night. He knew who it was.

The door slid up and there was Shiro. Sometimes Keith couldn’t help but wonder at their fortune, grateful that time and space had allowed them to be brought together. Keith knew that sometimes, Shiro looked at him in the exact same way.

Today, Keith didn’t see his gaze shared. Instead, Shiro’s head was cocked to the side, cold and teasing.

He instantly knew who it was by the way his heart hammered in his chest, and it wasn’t Shiro.

“It’s you again.” Keith said, flatly. “I don’t need this shit today, I’ll talk to you later.”

Keith reached to press the door close, watching as Shiro’s eyes flashed yellow when he snatched at his arm, pulling himself in before the door fully closed. With the florescent lighting of the hallway gone, the two of them were only lit by the dim lamp on Keith’s bedside table. Galaxies winking still from the window.

Keith wrenched his arm free, standing back at the wall next to the door. Shiro stood watching him, amused as the shorter young man suppressed a shudder. “What do you want?”

“Aw…,” a grin split across his mouth, “Don’t be like that. It’s me, your dear Shiro.”

“No, you’re not.” Keith responded, more venom in his voice than he anticipated. “You’re something… someone else. I don’t know who you are.”

“But you do.”

His voice was low, thick and supple like silk as it wound around Keith’s arms and legs, stilling him.

“You still don’t want to play?” Shiro took a stride towards Keith, and he stepped back, his elbows hitting the wall.

The imposing figure then took another step, their bodies now close enough that Keith could feel their breaths intermingling. Shiro brought up his GalraTech hand to cup Keith’s face, tilting it to the side and baring his neck. Languidly he licked the exposed clavicle at the collar of Keith’s shirt, up to the column of his neck. Keith bit back an unwilling moan, hand coming up to cover his mouth.

Shiro looked almost disappointed. “I thought you liked this.”

Keith said nothing. He felt something that he forced to hold back struggling to free itself, a constant battle with no winner at the end. “I… I don’t know…”

The taller man took the opportunity to lean over him, human arm bracing himself against the wall. Ever so slowly, his hand on Keith’s cheek slid down to hold his chin.

“Just give in.”

Their mouths met in a searing kiss, and Keith felt himself overwhelmed by a darkness, pulling him down.

If kisses from Shiro were made of starlight and smelled of freshly cut grass, then kisses from Shiro right now were made of black holes and smelled of the wind in a storm.

Gradually, hesitantly, Keith wound his hands around Shiro’s neck, his fingers reaching for the hairs at the back of his nape.

Shiro chuckled lowly into Keith’s mouth before he pulled at his bottom lip, biting at it gently before sucking it, feeling the way Keith shivered. Shiro’s tongue swiped against his lips, deceitfully casual. Keith knew that his asking was not a request, but a demand that bore consequences, and so he opened his mouth, letting the other inside. Their tongues made contact, and Shiro took the opportunity to suck Keith’s tongue, eliciting a surprised gasp from him. He could feel heat pool in his groin, and Shiro leaned in closely, pressing his thigh into the space between Keith’s legs.  

Their mouths parted, and he looked into Keith’s eyes, pupils blown with dizzying desire. He leaned in, close enough to almost kiss, but not quite.

“I knew you’d agree with me.”

Shiro’s hands traveled down Keith’s body leaving traces of fire in its wake. He whimpered as he strained to remain still under the touch, his fingernails digging into the back of Shiro’s neck.

“You know… Isn’t this better?” Shiro’s breath was hot, and he spoke in a way that made it apparent he was grinning.

He toyed with the edge of Keith’s shirt, skimming just underneath it with the most delicate touch, leaving Keith panting. As Shiro’s fingers lowered, he could feel his cock straining against his pants, betraying his emotions. The hands paused in their movement before lightly brushing against length, causing a sharp inhale to escape from his lips. But Shiro’s intent was to only tease and not satisfy, his hands rounding around to cup Keith’s ass.

“Isn’t it better that we do this…,” Shiro voice was just above a whisper, “Than for me to come out in the morning and be mean to all of your little friends?”

Keith bit his lip, refusing to give an answer.

Suddenly he grabbed ahold of Keith’s thighs. “What are you-?!” Keith’s hands came upward, clinging to Shiro’s hair as he was dragged upward against the wall.

Shiro groaned gutturally, ending in a hum that reverberated in his chest. “This way…”

He snapped his hips into Keith’s, grinding the hard lengths of their cocks against each other.

“I can spend my time fucking you senseless, and we both come up winning.”

Keith writhed against his movements, fingers pulling in a frenzied state at strands of hair on Shiro’s head. “Ha-aah! Shiro…” He breathed, feeling the thickness of Shiro’s desire for him with every thrust, rubbing roughly on his own.

“Mmmm…” Shiro hummed, licking the shell of Keith’s ear, pulling a moan from the other young man. “You should pull my hair more often… I know your sweet, naive Shiro would like it too.”

At the mention of it, Keith’s face turned an impossible red, already flushed from the shifting of Shiro’s hips. He turned his head to the side, looking away from him with the last shred of his dignity.

“Trying so hard to deny me…” Shiro laughed, nipping along the line of Keith’s now exposed neck. “Why don’t you just let go?”

He could barely process the words, light-headed from the pleasure coursing through his veins, yet feeling like a stone sinking into the ocean. The idea of relinquishing his self control, so tightly wound around his person, was inescapably attractive.

_Let Go_

And Keith fell, his mind becoming blank.

Shiro purred in approval, “Good little kitten,” sucking at the sensitive flesh just below Keith’s jawline, pausing to admire the wet, freshly made mark.  

He lowered Keith slowly to the ground, knees still weak from the assault that had just occurred moments before. “Shiro…” He whined, disappointed at the loss.

“Don’t worry, I still have other plans.” Came the response as Shiro held out his hand. The gesture was painful in its sudden gentleness, a sweet sensation filling Keith’s lungs. He took Shiro’s hand carefully, and found himself led back into his bed.

“Lie down.” The tone was forceful, commanding, and so Keith did. Heart thrumming, he laid there as he watched Shiro crawl onto the bed, sinuous as a predator that had just found prize prey. As he moved closer and closer, Keith found himself struggling not to stare, the sculpted muscles of Shiro’s arms putting on an impressive display. Finally Shiro rested on his knees, looking down at Keith with amusement. His body blocked the window, blotting out the starlight that could be seen beyond.

“You always struggle so magnificently.” Said Shiro as he took both of Keith’s arms in one hand, pushing them swiftly above his head. “But I think that’s what makes this all feel so good in the end.”

Keith could feel himself panting as he felt Shiro’s human hand make contact with the flat plain of his stomach, pushing the shirt upwards until he felt his entire abdomen exposed. The chill of the air made him involuntarily shiver, and Shiro bit his bottom lip in response. He began to rub slow circles on Keith’s stomach, smoothing his hand along the sides of his waist in feathering touches. Keith’s nipples pebbled, gasping Shiro’s name once again.

At the sight, Shiro licked his lips, wetting them as he spoke in a voice dark with need, “You look so wanton, the way you moan every time I touch you... especially here…”

His thumb drew a slow circle around Keith’s right nipple before flicking the nub, watching as the young man under him arched off the bed. “A-aah…!” Keith heard himself cry out, his mouth slack.

Shiro continued with his teasing, pinching and lightly twisting, watching with evident self-satisfaction. Slowly he lowered his head to Keith’s chest, taking the other nipple into his mouth with careful teeth and tongue. The sensations surged through Keith’s body like lightning, and he felt his cock, singing for release from its now too tight restraints. His hands, still pinned above his head, struggled for purchase on anything he could hold onto.    

“Shiro… haah, Shiro, I need-Haa-ah!” His plea to have his hands free cut off by another lap of Shiro’s tongue.

Finally he leaned back and let go, still sitting over Keith, his mouth wet. “What, little kitten?”  

He couldn’t muster the words, now that he had Shiro’s attention. With a flushed face his head turned again, revealing the previously made mark under his jaw.

“Tell me what you want.” Shiro leaned in closely, until he could hear the other man’s breath in his ear, feel it tingle his spine. Another demand, another thing he couldn’t refuse.

“I just want,” Keith bit his lower lip and Shiro groaned softly, carefully watching every movement, “I just want to be able to take off my pants… it’s getting to be too much…”

A deceptively gentle kiss was placed on his lips. “All you had to do was ask.”

Keith could suddenly feel the Shiro’s weight shift, and then he was off the bed all together. With his dark brows knitted in confusion and barely hidden dismay, he watched Shiro take a seat in his lounge chair, his legs splayed, posture loose, almost inviting.

 _Don’t fall for his trick._ Keith could hear the warning in his head.

“W-what are you doing?” Keith said as he sat up, forcing himself not to cringe at how tiny his voice sounded, uncertain. Shiro shrugged, his arms resting on each chair arm.

“You told me you wanted to take your clothes off.” He said nonchalantly before leaning forward, his hands now gripping the ends of the armrests, a glint of gold in his eye. “Why don’t you let me watch?”

Keith stilled.

“You don’t want to?” Shiro tilted his head and rested it on a hand, his face mocking disappointment.

His mouth felt dry as he answered. “I- I do… but-”

“Good. Then do it.” Shiro sat back, his other hand slowly running down his body before he cupped the hardness evident from the bulge in his pants. Languidly, he stroked the stilled clothed member, a low sound of pleasure escaping his lips. “I want to know that you want this as much as I do.”

The sight of Shiro touching himself in front of him was more than he could bear. More than anything, Keith wanted to join him and replace Shiro’s hand with his own, but the ever so slightly arched eyebrow told him to stay put, do what he was told.

And he did so desperately want to please Shiro.

With shaking fingers he pulled off his black t-shirt, his torso now completely bare.

“That’s good…” He heard Shiro purr from the chair at the foot of the bed.

At the sound of his voice so heavy-ladened with desire, Keith felt his nipples harden again, aching from the memory of being teased just moments earlier. He thumbed at the band of his pajama pants before taking those off as well. The only thing that remained was his underwear, the line of his cock unbearably clear. “W-what now?”

“Why don’t you touch yourself?” The suggestion, once again, felt as weighty as a command, Shiro’s voice rough. “I want to see you jerk off.”

Keith’s face reddened, his eyes already locked onto Shiro as he continued to fondle himself. It was only fair, he reasoned with himself. Shiro was already doing the same.

Slowly, torturously slowly for Shiro, Keith began to peel his boxer briefs off. His member sprang out from its confinement, precum already beading on its head. Keith shifted his weight to prop himself up on one hand, sitting on his knees. Distantly, he could hear Shiro hum with approval. With his other hand, his thumb swiped at the precum, smearing it on the rest of his shaft. Keith couldn’t bite back his groan, his entire body already shaking with gratification.

Emboldened by the sensations, his hand wrapped tightly around his cock, pumping it slowly. More sounds poured out as easy as breathing, his gaze now on his own performance, too embarrassed to look up at Shiro’s eyes. His pace quickened, and his grip around the shaft tightened, an innate desire to feel more, the pleasure curling his toes. Keith’s breaths became ragged, knowing that the stimulation was already becoming too much, but unable to stop from stroking himself.

“Stop.” Keith snapped his head upwards, looking finally at Shiro, noticing the way that Shiro’s chest moved up and down with heaving breaths. He let his hand drop, and his cock throbbed again, so close to completion.

“You look good, kitten.” Keith found himself blushing with pride at the praise. Shiro’s mouth moved into a smirk as he continued, “But… I also want to see you prepare yourself for me.”

Shiro’s new request, for some strange reason, seemed even more mortifyingly lewd than the first. Keith reeled at the idea of putting his own fingers into his ass, especially for Shiro to watch his every movement.  Even so, the ache in him had become enormous, and so he reached for his nightstand, pulling a bottle of lube from the drawer.

Shiro’s eyes never left Keith’s, watching as he slicked his fingers in the lubrication, the way the other young man shivered  as he gently probed his entrance. When the first finger went in, hesitantly thrusting in and out, Keith felt his mind go blank and his mouth fall open. He gazed down as his finger slipped in and of himself, his cock standing at attention. As he slipped his second finger in hungrily, he began to moan, calling out Shiro’s name.

“Tell me how much you want it.” He heard in response, another demand. “I want to hear how much you want me.”

He busily worked to stretch his entrance, his fleeting emotions of embarrassment gone, instead replaced with unadulterated, dizzying desire. Keith’s eyes slid heavily downward, losing focus as he continued to fuck himself with his fingers.

“Shiro…” He began, his words filled with gasps and whimpers, “I want you… I want your cock to fill me up. Look how much I want it.”

The room was filled with the perverse sound of his fingers as they wetly thrust into himself, searching for the one spot that would send his thoughts spiraling. “My fingers make me feel so good… But I want you instead. I want you to fuck me so hard, I won't be able to walk in the morning.”

A loud groan snapped Keith out of his trance, looking upward and to where Shiro sat. He hadn't realized before, but he had pulled out his own cock, impossibly thick and full with arousal. His hand, which had been lazily toying with himself, was now pumping up and down his shaft with urgency. 

The sight of Shiro was too much, enough to make his entire body ache in a way that was almost painful.

“Shiro, come here... please…” His legs widened, hips shifting upwards as he added a third finger. His voice was ragged and pitched with moans as he begged. “Come pin me down and pound me into the mattress.”

With a growl Shiro stood, unzipping his shirt and throwing it aside to reveal his impeccable physique and rippling abs.

“You did such a good job, fucking yourself as I watched.” he said, his voice could not be louder than a whisper, but just the immensity and weight of it made Keith moan again.

Shiro slowly walked back to the bed, once again moving as if a predator stalking soon devoured prey. When he reached Keith, he pulled the other young man’s hands aside, humming under his breath as he watched the slick digits slip out of his entrance. Before Keith even had a chance to whine, Shiro positioned his cock, rubbing it in circles around the hole and eliciting more moans from the both of them. “Are you ready for me to fuck you?”

Keith nodded hazily, and he felt Shiro push in, filling him so smoothly he almost couldn't breathe. Shiro’s hands moved to Keith’s waist, pulling torturously slowly out before roughly thrusting back in.

“Ngh-! Shiro…!” Keith cried out, not anticipating Shiro’s actions.

He heard a low chuckle, “I'm not playing anymore, kitten.”

Shiro began pounding into him at a relentless pace, his hands around Keith’s waist holding tight enough to bruise as he speared him on his cock. It was all Keith could do to hold on, his fingers digging and twisting into the sheets beneath him.

"Look at you…” Shiro breathed, “Look at how you're taking my cock in so deep. You like it, don't you? Being fucked so hard you can't see straight.”

His human hand moved upwards on the smooth plane of Keith’s chest before cupping his face almost tenderly. “Fuck… This is what you did to me by teasing yourself… and now the sounds you're making with that wet little mouth.”

Shiro slipped two fingers into Keith’s mouth, and without thinking, Keith began to suck on them, tongue coiling around the digits. At the sight, Shiro felt his member twitch, his pace quickening with a snap of his hips. Keith’s hole spasmed, clenching tightly.

“Shit…” Shiro murmured, “Maybe next time, I'll fuck that pretty little mouth. Would you like that Keith? I'll just hold your head with my hands and fuck your mouth until I cum into your throat, watch you as you swallow all of my load.”

Keith couldn't help but respond to the incredibly dirty words, letting out a pleasured sound that vibrated around Shiro’s fingers. Shiro pulled his fingers out, listening to Keith as he moaned, his body bouncing off the bed from the sheer force of his thrusts.

“I love it when you're like this.” He adjusted the angle of his hips, now driving directly into Keith’s prostate. In response, Keith let out a keening cry, one that Shiro took as approval.

“You’re so fucking sexy when you let go like this, practically impaled with my cock.” Keith’s hands were scrabbling, now holding onto the broad plane of Shiro’s back. “And I know you love it when I'm like this too.”

His fingers felt the way Shiro’s back muscles shifted and tensed, putting their full effort into offering him enough pleasure to push him past the brink of insanity. “Shiro…! Shiro I- I… Shiro I’m gonna-!”

Keith felt himself climbing, climbing higher and higher to his precipitous peak. He felt himself speaking and gasping nonsense, his voice filled with the need to release any of his need, his want in some way. Shiro leaned in closely, biting Keith’s ear as he writhed beneath him. Without warning, Shiro pulled his cock out of him only to flip him onto his stomach. Quickly dragging Keith’s body into a position that presented his ass to him, Shiro pushed back in, picking back up with the same ferocity as before.

Shiro bent over Keith’s back, one hand digging into to his hair, the other reaching around to pump Keith’s shaft in time with his thrusts.

“Shiro, I, I can't-!” Delirious, Keith felt his chest heave a sob, overwhelmed with the sensations washing over his body. It felt like Shiro was everywhere, an existence that filled him and covered every inch of his skin. “It’s too much-! I'm going to-”

“Then cum for me, kitten.” Shiro purred into closely to his ear, his voice panting.

With a half strangled cry, Keith climaxed, ribbons of cum spilling out on the sheets below him and into Shiro’s hand. An explosion of white filled his vision, followed by a kaleidoscope of falling stars. Keith felt himself fall with them.

With ringing ears, he heard Shiro give out a groan, followed by the sensation of hot semen pulsating and filling his insides.

Shiro pulled out, watching as his cum thickly leaked out of Keith’s entrance, his spent member still throbbing at the sight. Keith made it clear that he had no intention of moving, laying on his stomach while taking short breaths. Shiro reached to brush his hair, his hand met with Keith’s as he slapped it away.

“Don't do that,” Keith managed seething in his voice, despite his exhaustion. “Don't act like you're the same as Shiro.”

Tense silence filled the room for a moment before Shiro laughed. “Always so cold. Even when I work so hard to make you happy.”

“Only when you're like this.”

“Don't tell me you don't like it.” Shiro responded, and even though Keith’s face was still buried in a pillow, he knew the other man’s smile was sinister, eyes glimmering and yellow. He said nothing, trying to ignore the feeling of semen as it continued to leak out of him.

Shiro brushed his hand down Keith’s back, watched he shivered. “It doesn't matter. In the morning you’ll have your dear Shiro back. But when both you and I need it, you know you’ll be right here, waiting for me to fill you up with my cum again.”

Keith felt himself flush, a hand clenched into his sheets. It wasn't something he was going to deny, but it also wasn't something he was going to willingly agree to.

“I know that sometimes you need to lose control.” He heard Shiro continue, “And so do I.”

An arm came up to grab Keith’s free hand, rubbing the raised purplish scars on his palm. “Besides… It's not like I'm the only one with a secret.”

Keith felt as Shiro left the bed, gathered his shirt, and opened the door. With a hiss, he felt the door shut again, filling his room with an impossibly loud quiet.

In the dark light of his bedside lamp, he studied his scarred hand and closed his eyes.

Keith felt himself fall away, fall into a black hole, lost in space.

**Author's Note:**

> Thank you so much for reading my first smut fic... I've never attempted writing one before, and this wound up being a completely different monster than I anticipated.  
> You might have noticed that I mentioned potential Galran Keith... I wanted to leave it open for that to appear if I were to ever write a sequel, heh heh...  
> Nevertheless, thank you so so much for reading it completely through!


End file.
